package service

import (
	"context"
	"errors"
	"fmt"
	"strings"

	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
	m "gitlab.com/mbugroup/lti-api.git/internal/middleware"
	rProductWarehouse "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/product-warehouses/repositories"
	rStockTransfer "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/transfers/repositories"
	validation "gitlab.com/mbugroup/lti-api.git/internal/modules/inventory/transfers/validations"
	rSupplier "gitlab.com/mbugroup/lti-api.git/internal/modules/master/suppliers/repositories"
	warehouseRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/master/warehouses/repositories"
	projectFlockKandangRepo "gitlab.com/mbugroup/lti-api.git/internal/modules/production/project_flocks/repositories"
	rStockLogs "gitlab.com/mbugroup/lti-api.git/internal/modules/shared/repositories"
	"gitlab.com/mbugroup/lti-api.git/internal/utils"

	"github.com/go-playground/validator/v10"
	"github.com/gofiber/fiber/v2"
	"github.com/sirupsen/logrus"
	"gorm.io/gorm"
)

type TransferService interface {
	GetAll(ctx *fiber.Ctx, params *validation.Query) ([]entity.StockTransfer, int64, error)
	GetOne(ctx *fiber.Ctx, id uint) (*entity.StockTransfer, error)
	CreateOne(ctx *fiber.Ctx, req *validation.TransferRequest) (*entity.StockTransfer, error)
}

type transferService struct {
	Log                           *logrus.Logger
	Validate                      *validator.Validate
	StockTransferRepo             rStockTransfer.StockTransferRepository
	StockTransferDetailRepo       rStockTransfer.StockTransferDetailRepository
	StockTransferDeliveryRepo     rStockTransfer.StockTransferDeliveryRepository
	StockTransferDeliveryItemRepo rStockTransfer.StockTransferDeliveryItemRepository
	StockLogsRepository           rStockLogs.StockLogRepository
	ProductWarehouseRepo          rProductWarehouse.ProductWarehouseRepository
	SupplierRepo                  rSupplier.SupplierRepository
	WarehouseRepo                 warehouseRepo.WarehouseRepository
	ProjectFlockKandangRepo       projectFlockKandangRepo.ProjectFlockKandangRepository
}

func NewTransferService(validate *validator.Validate, stockTransferRepo rStockTransfer.StockTransferRepository, stockTransferDetailRepo rStockTransfer.StockTransferDetailRepository, stockTransferDeliveryRepo rStockTransfer.StockTransferDeliveryRepository, stockTransferDeliveryItemRepo rStockTransfer.StockTransferDeliveryItemRepository, stockLogsRepo rStockLogs.StockLogRepository, productWarehouseRepo rProductWarehouse.ProductWarehouseRepository, supplierRepo rSupplier.SupplierRepository, warehouseRepo warehouseRepo.WarehouseRepository, projectFlockKandangRepo projectFlockKandangRepo.ProjectFlockKandangRepository) TransferService {
	return &transferService{
		Log:                           utils.Log,
		Validate:                      validate,
		StockTransferRepo:             stockTransferRepo,
		StockTransferDetailRepo:       stockTransferDetailRepo,
		StockTransferDeliveryRepo:     stockTransferDeliveryRepo,
		StockTransferDeliveryItemRepo: stockTransferDeliveryItemRepo,
		StockLogsRepository:           stockLogsRepo,
		ProductWarehouseRepo:          productWarehouseRepo,
		SupplierRepo:                  supplierRepo,
		WarehouseRepo:                 warehouseRepo,
		ProjectFlockKandangRepo:       projectFlockKandangRepo,
	}
}
func (s transferService) withRelations(db *gorm.DB) *gorm.DB {
	return db.
		Preload("CreatedUser").
		Preload("FromWarehouse").
		Preload("FromWarehouse.Location").
		Preload("FromWarehouse.Area").
		Preload("ToWarehouse").
		Preload("ToWarehouse.Location").
		Preload("ToWarehouse.Area").
		Preload("Details").
		Preload("Details.Product").
		Preload("Deliveries.Items").
		Preload("Deliveries.Supplier")
}

func (s transferService) GetAll(c *fiber.Ctx, params *validation.Query) ([]entity.StockTransfer, int64, error) {
	if err := s.Validate.Struct(params); err != nil {
		return nil, 0, err
	}

	offset := (params.Page - 1) * params.Limit

	transfers, total, err := s.StockTransferRepo.GetAll(c.Context(), offset, params.Limit, func(db *gorm.DB) *gorm.DB {
		db = s.withRelations(db)
		if params.Search != "" {
			db = db.Where("movement_number LIKE ?", "%"+strings.TrimSpace(params.Search)+"%")
		}
		return db.Order("created_at DESC").Order("updated_at DESC")
	})

	if err != nil {
		return nil, 0, err
	}

	s.Log.Infof("Retrieved %d transfers", len(transfers))

	return transfers, total, nil

}

func (s transferService) GetOne(c *fiber.Ctx, id uint) (*entity.StockTransfer, error) {
	var transfer entity.StockTransfer

	// gunakan repo secara langsung
	transferPtr, err := s.StockTransferRepo.GetByID(c.Context(), id, func(db *gorm.DB) *gorm.DB {
		return s.withRelations(db)
	})
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, fiber.NewError(fiber.StatusNotFound, "Transfer not found")
		}
		s.Log.Errorf("Failed to get transfer by ID: %+v", err)
		return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to get transfer")
	}

	s.Log.Infof("Retrieved transfer: %+v", transfer)

	return transferPtr, nil
}

func (s *transferService) CreateOne(c *fiber.Ctx, req *validation.TransferRequest) (*entity.StockTransfer, error) {

	// Validasi stok di gudang asal harus exist dan mencukupi
	for _, product := range req.Products {
		sourcePW, err := s.ProductWarehouseRepo.GetProductWarehouseByProductAndWarehouseID(
			c.Context(), uint(product.ProductID), uint(req.SourceWarehouseID),
		)
		if err != nil {
			if errors.Is(err, gorm.ErrRecordNotFound) {
				return nil, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Stok produk %d tidak tersedia di gudang asal", product.ProductID))
			}
			return nil, fiber.NewError(fiber.StatusInternalServerError, "Gagal cek stok produk di gudang asal")
		}
		if sourcePW.Quantity < product.ProductQty {
			return nil, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Stok produk %d di gudang asal tidak cukup", product.ProductID))
		}
	}
	actorID, err := m.ActorIDFromContext(c)
	if err != nil {
		return nil, err
	}

	// validasi total qty harus lebih besar dari atau sama dengan total qty di delivery compare berdasarkan productid
	deliveryQtyMap := make(map[uint]float64)
	for _, delivery := range req.Deliveries {
		for _, prod := range delivery.Products {
			deliveryQtyMap[prod.ProductID] += prod.ProductQty
		}
	}

	// Cek: qty delivery tidak boleh melebihi qty di root
	for _, product := range req.Products {
		if deliveryQtyMap[product.ProductID] > product.ProductQty {
			return nil, fiber.NewError(fiber.StatusBadRequest,
				fmt.Sprintf("Total qty delivery untuk produk %d (%v) melebihi qty transfer (%v)", product.ProductID, deliveryQtyMap[product.ProductID], product.ProductQty))
		}
	}

	// cek suplier id caegory BOP cek by id
	for _, delivery := range req.Deliveries {
		supplier, err := s.SupplierRepo.GetByID(c.Context(), uint(delivery.SupplierID), nil)
		if err != nil {
			if errors.Is(err, gorm.ErrRecordNotFound) {
				return nil, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Supplier dengan ID %d tidak ditemukan", delivery.SupplierID))
			}
			return nil, fiber.NewError(fiber.StatusInternalServerError, "Gagal cek data supplier")
		}
		if supplier.Category != "BOP" {
			return nil, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Supplier dengan ID %d bukan kategori BOP", delivery.SupplierID))
		}
	}

	// Generate movement number
	// Format: PND-MBU-00001
	seqNum, err := s.StockTransferRepo.GetNextMovementNumber(c.Context())
	if err != nil {
		s.Log.Errorf("Failed to get next movement number: %+v", err)
		return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to generate movement number")
	}
	movementNumber := fmt.Sprintf("PND-MBU-%05d", seqNum)
	transferDate, _ := utils.ParseDateString(req.TransferDate)

	entityTransfer := &entity.StockTransfer{
		FromWarehouseId: uint64(req.SourceWarehouseID),
		ToWarehouseId:   uint64(req.DestinationWarehouseID),
		Reason:          req.TransferReason,
		TransferDate:    transferDate,
		MovementNumber:  movementNumber,
		CreatedBy:       uint64(actorID),
	}

	// Save the transfer entity to the database
	err = s.StockTransferRepo.DB().WithContext(c.Context()).Transaction(func(tx *gorm.DB) error {

		// Insert header
		if err := s.StockTransferRepo.WithTx(tx).CreateOne(c.Context(), entityTransfer, nil); err != nil {
			s.Log.Errorf("Failed to create stock transfer: %+v", err)
			return err
		}
		s.Log.Infof("Stock transfer created: %+v", entityTransfer.Id)

		// insert ke details
		var details []*entity.StockTransferDetail
		for _, product := range req.Products {
			details = append(details, &entity.StockTransferDetail{
				StockTransferId: entityTransfer.Id,
				ProductId:       uint64(product.ProductID),
				Quantity:        product.ProductQty,
			})
		}
		if err := s.StockTransferDetailRepo.WithTx(tx).CreateMany(c.Context(), details, nil); err != nil {
			s.Log.Errorf("Failed to create stock transfer details: %+v", err)
			return err
		}
		s.Log.Infof("Stock transfer details created for transfer ID: %+v", entityTransfer.Id)

		// Tambahkan proses insert delivery
		var deliveries []*entity.StockTransferDelivery
		for _, delivery := range req.Deliveries {
			deliveries = append(deliveries, &entity.StockTransferDelivery{
				StockTransferId:   entityTransfer.Id,
				SupplierId:        uint64(delivery.SupplierID),
				VehiclePlate:      delivery.VehiclePlate,
				DriverName:        delivery.DriverName,
				DocumentPath:      "https://tourism.gov.in/sites/default/files/2019-04/dummy-pdf_2.pdf", // todo: tunggu ada aws baru proses
				ShippingCostItem:  delivery.DeliveryCostPerItem,
				ShippingCostTotal: delivery.DeliveryCost,
			})
		}
		if err := s.StockTransferDeliveryRepo.WithTx(tx).CreateMany(c.Context(), deliveries, nil); err != nil {
			s.Log.Errorf("Failed to create stock transfer deliveries: %+v", err)
			return err
		}
		// tambahkan insert ke delivery items sebagai pivot
		detailMap := make(map[uint64]uint64)
		for _, d := range details {
			detailMap[d.ProductId] = d.Id
		}

		var deliveryItems []*entity.StockTransferDeliveryItem

		for i, delivery := range deliveries {
			item := req.Deliveries[i]
			for _, prod := range item.Products {
				detailID, ok := detailMap[uint64(prod.ProductID)]
				if !ok {
					return fmt.Errorf("produk %d tidak ditemukan di detail", prod.ProductID)
				}
				deliveryItems = append(deliveryItems, &entity.StockTransferDeliveryItem{
					StockTransferDeliveryId: delivery.Id,
					StockTransferDetailId:   detailID,
					Quantity:                prod.ProductQty,
				})
			}
		}
		if err := s.StockTransferDeliveryItemRepo.WithTx(tx).CreateMany(c.Context(), deliveryItems, nil); err != nil {
			s.Log.Errorf("Failed to create stock transfer delivery items: %+v", err)
			return err
		}
		s.Log.Infof("Stock transfer delivery items created for transfer ID: %+v", entityTransfer.Id)

		// Proses pengurangan stok di gudang asal dan penambahan stok di gudang tujuan
		for _, product := range req.Products {
			// Kurangi stok di gudang asal
			sourcePW, err := s.ProductWarehouseRepo.GetProductWarehouseByProductAndWarehouseID(c.Context(), uint(product.ProductID), uint(req.SourceWarehouseID))
			if err != nil {
				s.Log.Errorf("Failed to get source product warehouse: %+v", err)
				return fiber.NewError(fiber.StatusInternalServerError, "Failed to get source product warehouse")
			}
			if sourcePW.Quantity < product.ProductQty {
				s.Log.Errorf("Insufficient stock in source warehouse for product ID: %+v", product.ProductID)
				return fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Insufficient stock in source warehouse for product ID: %d", product.ProductID))
			}
			sourcePW.Quantity -= product.ProductQty
			if err := s.ProductWarehouseRepo.WithTx(tx).UpdateOne(c.Context(), sourcePW.Id, sourcePW, nil); err != nil {
				s.Log.Errorf("Failed to update source product warehouse: %+v", err)
				return err
			}
			s.Log.Infof("Source product warehouse updated: %+v", sourcePW.Id)

			// create stock log for decrease (source)
			// beforeQty := sourcePW.Quantity + product.ProductQty // sourcePW already decreased
			decreaseLog := &entity.StockLog{
				// TransactionType:    entity.TransactionTypeDecrease,
				// Quantity:           product.ProductQty,
				// BeforeQuantity:     beforeQty,
				// AfterQuantity:      sourcePW.Qty,
				// LogType:            entity.LogTypeTransfer,
				// LogId:              uint(entityTransfer.Id),
				Decrease:           product.ProductQty,
				Notes:              "",
				LoggableType:       entity.LogTypeTransfer,
				LoggableId:         uint(entityTransfer.Id),
				ProductWarehouseId: sourcePW.Id,
				CreatedBy:          actorID,
			}
			if err := s.StockLogsRepository.WithTx(tx).CreateOne(c.Context(), decreaseLog, nil); err != nil {
				s.Log.Errorf("Failed to create stock log decrease: %+v", err)
				return err
			}

			// Tambah stok di gudang tujuan
			destPW, err := s.ProductWarehouseRepo.GetProductWarehouseByProductAndWarehouseID(
				c.Context(), uint(product.ProductID), uint(req.DestinationWarehouseID),
			)
			if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
				s.Log.Errorf("Failed to get destination product warehouse: %+v", err)
				return fiber.NewError(fiber.StatusInternalServerError, "Failed to get destination product warehouse")
			}
			if err != nil && errors.Is(err, gorm.ErrRecordNotFound) {
				// Jika belum ada record untuk produk di gudang tujuan, buat baru
				ctx := c.Context()
				projectFlockKandangID, err := s.getActiveProjectFlockKandangID(ctx, uint(req.DestinationWarehouseID))
				if err != nil {
					return err
				}
				destPW = &entity.ProductWarehouse{
					ProductId:             uint(product.ProductID),
					WarehouseId:           uint(req.DestinationWarehouseID),
					Quantity:              0,
					ProjectFlockKandangId: &projectFlockKandangID,
					// CreatedBy:   1, // TODO: should Get from auth middleware
				}
				if err := s.ProductWarehouseRepo.WithTx(tx).CreateOne(c.Context(), destPW, nil); err != nil {
					s.Log.Errorf("Failed to create destination product warehouse: %+v", err)
					return fiber.NewError(fiber.StatusInternalServerError, "Failed to create destination product warehouse")
				}
				s.Log.Infof("Destination product warehouse created: %+v", destPW.Id)
			}
			// Update stok di gudang tujuan
			destPW.Quantity += product.ProductQty
			if err := s.ProductWarehouseRepo.WithTx(tx).UpdateOne(c.Context(), destPW.Id, destPW, nil); err != nil {
				s.Log.Errorf("Failed to update destination product warehouse: %+v", err)
				return err
			}
			s.Log.Infof("Destination product warehouse updated: %+v", destPW.Id)

			// create stock log for increase (destination)
			// beforeDestQty := destPW.Quantity - product.ProductQty
			increaseLog := &entity.StockLog{
				// TransactionType:    entity.TransactionTypeIncrease,
				// Quantity:           product.ProductQty,
				// BeforeQuantity:     beforeDestQty,
				// AfterQuantity:      destPW.Qty,
				Increase:           product.ProductQty,
				LoggableType:       entity.LogTypeTransfer,
				LoggableId:         uint(entityTransfer.Id),
				Notes:              "",
				ProductWarehouseId: destPW.Id,
				CreatedBy:          actorID,
			}
			if err := s.StockLogsRepository.WithTx(tx).CreateOne(c.Context(), increaseLog, nil); err != nil {
				s.Log.Errorf("Failed to create stock log increase: %+v", err)
				return err
			}

		}

		return nil
	})

	if err != nil {
		s.Log.Errorf("Transaction failed in CreateOne: %+v", err)
		return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to process transfer transaction")
	}

	// Ambil data lengkap hasil create dengan GetOne (agar preload relasi sama dengan GetOne)
	result, err := s.GetOne(c, uint(entityTransfer.Id))
	if err != nil {
		return nil, err
	}
	return result, nil
}

func (s *transferService) getActiveProjectFlockKandangID(ctx context.Context, warehouseID uint) (uint, error) {
	warehouse, err := s.WarehouseRepo.GetByID(ctx, warehouseID, nil)
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return 0, fiber.NewError(fiber.StatusNotFound, fmt.Sprintf("Gudang dengan ID %d tidak ditemukan", warehouseID))
		}
		s.Log.Errorf("Failed to get warehouse %d: %+v", warehouseID, err)
		return 0, fiber.NewError(fiber.StatusInternalServerError, "Gagal mengambil data gudang")
	}

	if warehouse.KandangId == nil || *warehouse.KandangId == 0 {
		return 0, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Gudang %d belum terhubung ke kandang", warehouseID))
	}

	projectFlockKandang, err := s.ProjectFlockKandangRepo.GetActiveByKandangID(ctx, uint(*warehouse.KandangId))
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return 0, fiber.NewError(fiber.StatusBadRequest, fmt.Sprintf("Kandang %d belum memiliki project flock aktif", *warehouse.KandangId))
		}
		s.Log.Errorf("Failed to get active project flock for kandang %d: %+v", *warehouse.KandangId, err)
		return 0, fiber.NewError(fiber.StatusInternalServerError, "Gagal mengambil project flock kandang")
	}

	return uint(projectFlockKandang.Id), nil
}